From 1989 to 1990, he directed the Nahan gallery in SoHo in New York City[1] where he curated a dozen exhibitions of both emerging and established artists, including Carolee Schneemann, Nancy Grossman, Hung Liu, Hong-Wen Lin, Robert Barry, Douglas Huebler, Mel Bochner, Antoni Muntadas, and Max Ernst.
His book on the American conceptualist Robert Barry was published by Karl Kerber Press in Bielefeld, Germany (1986).
His Turkish Bath installation at Artists Space in 1976 has been recognized an early example of post-conceptual art.
His critical anthologies on Gary Hill (2000) and Bruce Nauman (2002) were published by Johns Hopkins University Press.
An edited volume of the late writings by the critic Clement Greenberg was published by the University of Minnesota Press in 2003.